DESCRIPTION:
This fault code sets when the pressure drop between the diesel oxidation catalyst (DOC) inlet pressure or diesel particulate filter (DPF) outlet pressure is not within an expected value.

MONITORED PARAMETER:
DOC inlet pressure sensor and DPF outlet pressure sensor.

TYPICAL ENABLING CONDITIONS:
Always on

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
Two seconds

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
1. Drat 25%
2. EGR shut off
3. Regen inhibited

VERIFICATION:
Run engine between 1200 to 1800 rpm with a load less than 10%.

PROBABLE CAUSES:
1. DOC inlet pressure sensor.
2. DPF outlet pressure sensor.
3. Check all electrical connections upstream of the ECM.
4. DOC pressure sensor tube plugged.
5. DOC pressure sensor elbow plugged.
6. Perform stationary regen.